Relation between left ventricular outflow tract obstruction and left ventricular shape in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance imaging study.

Hypertrophic cardiomyopathies (HCM) are often associated with left ventricular (LV) outflow tract obstruction, which can explain symptoms and impact prognosis. To better understand the mechanisms that link obstruction and LV shape in HCM. Patients with HCM who underwent cardiac magnetic resonance (CMR) imaging were included retrospectively. Obstructive HCM was defined as LV outflow gradient more than 30 mm Hg at rest by transthoracic echocardiography. The LV shape and mitral angle were assessed by CMR. Results were compared with control subjects. Mean LV-mitral angle was smaller in patients with obstructive HCM (n=29) than in patients with non-obstructive HCM (n=15) or control subjects (n=15) (80 ± 5° vs 87 ± 7° [P=0.0002] and 89 ± 2° [P<0.0001]). Mean mitral papillary muscles angle was greater in patients with non-obstructive HCM than in patients with obstructive HCM or control subjects (136 ± 17° vs 123 ± 16° [P=0.007] and 118 ± 10° [P=0.002]). Patients with non-obstructive HCM had a greater mean LV-aortic root angle than patients with obstructive HCM or control subjects (139 ± 6° vs 135 ± 7° [P=0.04] and 133 ± 7° [P=0.03]). There is a relation between morphological and functional parameters in HCM within which the mitral valve is probably part of pathophysiogenesis.

Martin R ，Lairez O ，Boudou N ，Méjean S ，Lhermusier T ，Dumonteil N ，Berry M ，Cognet T ，Massabuau P ，Elbaz M ，Rousseau H ，Galinier M ，Carrié D ... -  《-》

Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy Patients Without Severe Septal Hypertrophy: Implications of Mitral Valve and Papillary Muscle Abnormalities Assessed Using Cardiac Magnetic Resonance and Echocardiography.

In patients with hypertrophic cardiomyopathy and left ventricular outflow tract (LVOT) obstruction, but without basal septal hypertrophy, we sought to identify mitral valve (MV) and papillary muscle (PM) abnormalities that predisposed to LVOT obstruction, using echo and cardiac magnetic resonance. We studied 121 patients with hypertrophic cardiomyopathy hypertrophic cardiomyopathy (age, 49±17 years; 60% men; 57% on β-blockers) with a basal septal thickness of ≤1.8 cm who underwent echocardiography (rest+stress) and cine cardiac magnetic resonance. Echo measurements included maximal LVOT gradient (rest/provocable), MV leaflet length (parasternal long, 4 and 3-chamber views), and abnormal chordal attachment to mid/base of anterior MV. Cine cardiac magnetic resonance measurements included basal septal thickness, number/area of PM heads, and bifid PM mobility (in systole and diastole). Mean basal septal thickness, LVOT gradient, and LV ejection fraction were 1.5±0.3 cm, 72±54 mm Hg, and 61±6%, respectively. The number of anterolateral and posteromedial PM heads was 2.7±0.7 and 2.6±0.7, respectively. Anterolateral and posteromedial PM areas were 19.9±7 cm(2) and 17.1±6 cm(2), respectively. PM mobility was 11±6°. On multivariable analysis, predictors of maximal LVOT gradient were basal septal thickness, bifid PM mobility, anterior mitral leaflet length, and abnormal chordal attachment to base of anterior mitral leaflet. Forty-five patients underwent surgery to relieve LVOT obstruction, of which 52% needed an additional nonmyectomy (MV repair/replacement or PM reorientation) approach. In hypertrophic cardiomyopathy patients without significant LV hypertrophy, in addition to basal septal thickness, anterior MV length, abnormal chordal attachment, and bifid PM mobility are associated with LVOT obstruction. In such patients, additional procedures on MV and PM (±myectomy) could be considered.

Patel P ，Dhillon A ，Popovic ZB ，Smedira NG ，Rizzo J ，Thamilarasan M ，Agler D ，Lytle BW ，Lever HM ，Desai MY ... -  《-》

Steep left ventricle to aortic root angle and hypertrophic obstructive cardiomyopathy: study of a novel association using three-dimensional multimodality imaging.

Kwon DH ，Smedira NG ，Popovic ZB ，Lytle BW ，Setser RM ，Thamilarasan M ，Schoenhagen P ，Flamm SD ，Lever HM ，Desai MY ... -  《-》

Mitral valve abnormalities identified by cardiovascular magnetic resonance represent a primary phenotypic expression of hypertrophic cardiomyopathy.

Maron MS ，Olivotto I ，Harrigan C ，Appelbaum E ，Gibson CM ，Lesser JR ，Haas TS ，Udelson JE ，Manning WJ ，Maron BJ ... -  《-》

Quantification of mitral regurgitation in patients with hypertrophic cardiomyopathy using aortic and pulmonary flow data: impacts of left ventricular outflow tract obstruction and different left ventricular segmentation methods.

Śpiewak M ，Kłopotowski M ，Gawor M ，Kubik A ，Kowalik E ，Miłosz-Wieczorek B ，Dąbrowski M ，Werys K ，Mazurkiewicz Ł ，Kożuch K ，Polańska-Skrzypczyk M ，Petryka-Mazurkiewicz J ，Klisiewicz A ，Bilińska ZT ，Grzybowski J ，Witkowski A ，Marczak M ... -  《-》